Efficient asymmetric transfer hydrogenation of ketones in ethanol with chiral iridium complexes of spiroPAP ligands as catalysts

Highly efficient iridium catalyzed asymmetric transfer hydrogenation of simple ketones with ethanol as a hydrogen donor has been developed. By using chiral spiro iridium catalysts (S)-1a a series of alkyl aryl ketones were hydrogenated to chiral alcohols with up to 98% ee.